/**
 * Software License, Version 1.0
 * 
 * Copyright 2003 The Trustees of Indiana University.  All rights reserved.
 * 
 *
 *Redistribution and use in source and binary forms, with or without 
 *modification, are permitted provided that the following conditions are met:
 *
 *1) All redistributions of source code must retain the above copyright notice,
 * the list of authors in the original source code, this list of conditions and
 * the disclaimer listed in this license;
 *2) All redistributions in binary form must reproduce the above copyright 
 * notice, this list of conditions and the disclaimer listed in this license in
 * the documentation and/or other materials provided with the distribution;
 *3) Any documentation included with all redistributions must include the 
 * following acknowledgement:
 *
 *"This product includes software developed by the Community Grids Lab. For 
 * further information contact the Community Grids Lab at 
 * http://communitygrids.iu.edu/."
 *
 * Alternatively, this acknowledgement may appear in the software itself, and 
 * wherever such third-party acknowledgments normally appear.
 * 
 *4) The name Indiana University or Community Grids Lab or NaradaBrokering, 
 * shall not be used to endorse or promote products derived from this software 
 * without prior written permission from Indiana University.  For written 
 * permission, please contact the Advanced Research and Technology Institute 
 * ("ARTI") at 351 West 10th Street, Indianapolis, Indiana 46202.
 *5) Products derived from this software may not be called NaradaBrokering, 
 * nor may Indiana University or Community Grids Lab or NaradaBrokering appear
 * in their name, without prior written permission of ARTI.
 * 
 *
 * Indiana University provides no reassurances that the source code provided 
 * does not infringe the patent or any other intellectual property rights of 
 * any other entity.  Indiana University disclaims any liability to any 
 * recipient for claims brought by any other entity based on infringement of 
 * intellectual property rights or otherwise.  
 *
 *LICENSEE UNDERSTANDS THAT SOFTWARE IS PROVIDED "AS IS" FOR WHICH NO 
 *WARRANTIES AS TO CAPABILITIES OR ACCURACY ARE MADE. INDIANA UNIVERSITY GIVES
 *NO WARRANTIES AND MAKES NO REPRESENTATION THAT SOFTWARE IS FREE OF 
 *INFRINGEMENT OF THIRD PARTY PATENT, COPYRIGHT, OR OTHER PROPRIETARY RIGHTS. 
 *INDIANA UNIVERSITY MAKES NO WARRANTIES THAT SOFTWARE IS FREE FROM "BUGS", 
 *"VIRUSES", "TROJAN HORSES", "TRAP DOORS", "WORMS", OR OTHER HARMFUL CODE.  
 *LICENSEE ASSUMES THE ENTIRE RISK AS TO THE PERFORMANCE OF SOFTWARE AND/OR 
 *ASSOCIATED MATERIALS, AND TO THE PERFORMANCE AND VALIDITY OF INFORMATION 
 *GENERATED USING SOFTWARE.
 */
package cgl.narada.util;

import java.util.Random;
/**
   Displays the progress on the command line. 

   @author Shrideep Pallickara
   $Date$
   $Revision$
*/

public class ProgressIndicator {

  public void showUpdate(long currentValue, long previousValue, 
			 String endingSuffix) {
    
    if (currentValue >= previousValue) {
      showProgress(currentValue, previousValue, endingSuffix);
      return;
    }
    
    double valCurrentLogBase10 = 
      Math.log((double)currentValue)/Math.log((double)10);
    
    double valPreviousLogBase10 = 
      Math.log((double)previousValue)/Math.log((double)10);

    int valCurrent  = (int) valCurrentLogBase10;
    int valPrevious = (int) valPreviousLogBase10;

    int eraseFirst = valPrevious + endingSuffix.length() + 1;
    
    for (int j=0; j <= eraseFirst; j++) {
      System.out.print("\b");
    }

    System.out.print(currentValue + endingSuffix);
    
    for (int i=0; i < (valPrevious-valCurrent); i++) {
      System.out.print(" ");
      System.out.print("\b");
    }
  }


  public void showProgress(long currentValue, long previousValue, 
			   String endingSuffix) {
    double valLogBase10 = Math.log((double)previousValue)/Math.log((double)10);
    
    int spaceToErase = (int) valLogBase10;
    
    int goBack = endingSuffix.length() + spaceToErase;
    
    if (previousValue == 0 && currentValue == 0) {
      goBack+= goBack; 
    }
    
    
    for (int j=0; j <= goBack; j++) {
      System.out.print("\b");
    }
    System.out.print(currentValue + endingSuffix);
  }


  public static void main(String[] args) {
    System.out.println("Testing the progress indicator \n");
    long startTime = System.currentTimeMillis();
    ProgressIndicator pi = new ProgressIndicator();
    long elapsedTime = 0;
    long oldElapsedTime=0;
    Random random = new Random();
    int doTill = 123;
    for (int i=1; i< doTill; i++) {
      //elapsedTime = System.currentTimeMillis() - startTime;
      //elapsedTime = i;
      //elapsedTime = random.nextInt(i);

      double percentComplete =   
	Math.floor ( (  ((double)i/(double)doTill) * 100 ) );
      elapsedTime = (long) percentComplete;
      
      //elapsedTime*=100;
      pi.showUpdate(elapsedTime, oldElapsedTime, " % completed");
      //pi.showUpdate(elapsedTime, oldElapsedTime, " mSecs");
      
      try {
	Thread.currentThread().sleep(30);
      } catch(InterruptedException ie)  {
	System.out.println(ie);
      }/*end try-catch */
      oldElapsedTime = elapsedTime;
    }/* end for */
    
  }/* end main() */
}
